1. Field of Invention
This invention relates to a liquid softening agent for a woven fabric which has an excellent flowability as well as stability, and can impart softness to clothes made of a variety of hydrophilic and hydrophobic materials.
2. Description of Prior Art
Almost all softening agents for household use that are put on the market at present are of the composition consisting predominantly of a quaternary ammonium salt which has two long-chain alkyl groups in 1 molecule thereof. To use the composition for household use easily, most of them are liquefied. Though the quaternary ammonium salt per se is hydrophilic, it has a small solubility in water. If the quaternary ammonium salt, as it is, is kept as an aqueous solution of a high concentration, it changes easily to a gel-like state whereby the preparation of a stable composition of a low viscosity becomes almost impossible.
In order to solve the problems, attempts have been made to obtain a more stable composition having a low viscosity by adding to the quaternary ammonium salt various additives such as a solvent, an inorganic salt, a nonionic surface active agent, a cationic activator such as mono-long-chain alkyl quaternary ammonium salts, and the like.
These methods, however, fail to sufficiently satisfy the required dispersion stability as well as recovery from freezing at various temperatures without causing any disadvantage on the softness.
Since the above-mentioned quaternary ammonium salt is used as a principal component of softening agents for household use available nowadays, further, the agents can provide only inferior effects for synthetic fibers such as acrylic-type, polyamide-type, etc., although they exhibit a remarkable effect on cottons. On the contrary, softening agents for an industrial use, but not for household use, hardly exhibit any effect on cottons.